DFT Insights into the electronic, optical, elastic, mechanical, and anisotropic profiles of 2D Ni2PS2 and Ni2PSe2

We present a comprehensive investigation of the electronic, optical, elastic, mechanical, and anisotropic properties of 2D Ni₂PS₂ and Ni₂PSe₂ via density functional theory (DFT). The electronic band results indicate a metallic nature, predominantly governed by d-orbital contributions to the conductivity in both materials. Optical analysis reveals significant absorption, pronounced dielectric behavior, and substantial optical conductivity. These properties render the materials suitable for optoelectronic applications and as high-k dielectric alternatives. The optical profiles indicate a considerable capacity for utilization in energy storage applications, particularly in the domains of supercapacitors and battery electrodes. Ni₂PSe₂ exhibits enhanced photon absorption in the infrared and visible spectra, resulting in enhanced carrier dynamics. Mechanical assessments verify their stability, which is supported by elastic stiffness constants that fulfill Born’s criteria. Both materials exhibit ductility, as confirmed by their high Pugh ratio and Poisson’s ratio values, ensuring their resilience in practical applications. Furthermore, Ni₂PSe₂ displays pronounced elastic anisotropy, which is particularly advantageous for advanced technologies requiring directional mechanical performance. The present findings contribute to an enhanced comprehension of 2D metal phosphorous dichalcogenides, thereby expanding their potential applications in next-generation electronic, photonic, energy storage, and mechanically robust systems.